A detailed study on the cooking kinetics of fresh and hard to cook common beans (Phaseolus vulgaris L.): A case study on bean accessions of different market classes

A large-scale study was conducted to obtain a more holistic understanding of the cooking behavior for different bean accessions in terms of cooking kinetics and time to cook. Fresh and aged soaked beans from twenty-four accessions were assessed for texture evolution during cooking at 95 °C using the most informative objective compression texture analysis method. Texture evolution was modelled by the conventional fractional conversion model as well as modified three-parameter models to capture the lag phase. The initial texture varied across bean accessions and is significantly positively related to bean size. Significant but limited differences in initial texture on ageing were observed, the difference being accession dependent. The texture evolution during cooking, cooking kinetics and time to cook varied across bean accessions and storage conditions and all bean accessions developed the hard to cook defect. The softening rate constants for fresh beans were significantly higher (0.026–0.053) and more variable than for aged beans (0.008–0.014, almost similar values). Fresh and aged beans of a given accession softened to similar levels of final relative hardness. The lag phase was more prominent in aged beans (up to ≈25 min) than non-aged beans (0–7 min). Therefore, the difference in time to cook for fresh beans across accessions is mainly determined by the difference in initial hardness and cooking rate constant, while for aged beans these differences depend on initial hardness and lag time and to a lesser extent on the cooking rate constant.